A Holographic Single-Pixel Stereo Camera Sensor for Calibration-free Eye-Tracking in Retinal Projection Augmented Reality Glasses

Eye-tracking is a key technology for future retinal projection based AR glasses as it enables techniques such as foveated rendering or gaze-driven exit pupil steering, which both increases the system's overall performance. However, two of the major challenges video oculography systems face are robust gaze estimation in the presence of glasses slippage, paired with the necessity of frequent sensor calibration. To overcome these challenges, we propose a novel, calibration-free eye-tracking sensor for AR glasses based on a highly transparent holographic optical element (HOE) and a laser scanner. We fabricate a segmented HOE generating two stereo images of the eye-region. A single-pixel detector in combination with our stereo reconstruction algorithm is used to precisely calculate the gaze position. In our laboratory setup we demonstrate a calibration-free accuracy of 1.35° achieved by our eye-tracking sensor; highlighting the sensor's suitability for consumer AR glasses.